Multi-disc brake hub assembly with disc slide pins

ABSTRACT

A brake hub assembly including a hub defining a central axis, a plurality of guide pins, each of the plurality of guide pins extending from the hub and being generally aligned with the central axis, and a disc having at least two friction surfaces, the disc defining a plurality of guide pin receiving bores, wherein each of the plurality of guide pin receiving bores are positioned to receive an associated one of the plurality of guide pins therethrough such that the disc is moveable relative to the hub along the central axis.

BACKGROUND

The present application is directed to multi-disc brake hub assembliesand, more particularly, to multi-disc brake hub assemblies with discslide pins, one-piece springs or both.

Multi-disc brake assemblies typically include a hub, two discs, discsprings and a caliper assembly that includes a piston, a bracket, afist, an inner pad, a center pad and an outer pad. The hub includesmachined slots and the discs include splined teeth that slide within theslots in the hub. As brake pressure is applied, the piston advances theinner pad into the first disc, which advances the center pad into thesecond disc and ultimately into the outer pad, thereby applying abraking force to the discs.

Such multi-disc brake assemblies have presented several problems. In oneexample, the discs have exhibited a propensity for tipping out of theperpendicular plane, thereby reducing the braking performance. In asecond example, corrosion on the discs and hub has inhibited the abilityof the discs to freely slide, thereby presenting the risk of discsseizing to the hub.

Attempts to solve such problems have included the development of specialcoatings and treatments for limiting corrosion, as well as redesignadapted to reduce tipping. However, such attempts have resulting inincreased costs and more complex manufacturing and assemblyrequirements.

Accordingly, there is a need for a multi-disc brake hub assembly adaptedto reduce disc tipping, while providing enhanced disc slidingcapabilities at a relatively reduced cost.

SUMMARY

In one aspect, the disclosed multi-disc brake hub assembly may include ahub defining a central axis, a plurality of guide pins, each of theplurality of guide pins extending from the hub and being generallyaligned with the central axis, and a disc having two friction surfaces,the disc defining a plurality of guide pin receiving bores, wherein eachof the plurality of guide pin receiving bores are positioned to receivean associated one of the plurality of guide pins therethrough such thatthe disc is moveable relative to the hub along the central axis.

In another aspect, the disclosed multi-disc brake hub assembly mayinclude a hub defining a central axis and including a body and anannulet, the annulet defining a outer side and an inner side relative tothe central axis, a plurality of outer guide pins extending from theannulet on the outer side of the hub, each of the plurality of outerguide pins being generally aligned with the central axis, a plurality ofinner guide pins extending from the annulet on the inner side of thehub, each of the plurality of inner guide pins being generally alignedwith the central axis, an outer disc defining a plurality of guide pinreceiving bores positioned to receive an associated one of the pluralityof outer guide pins therethrough, wherein the outer disc is moveablealong the plurality of outer guide pins relative to the hub, and aninner disc defining a plurality of guide pin receiving bores positionedto receive an associated one of the plurality of inner guide pinstherethrough, wherein the inner disc is moveable along the plurality ofinner guide pins relative to the hub.

Also disclosed is a spring for applying a biasing force to a disc of amulti-disc brake hub assembly including a hub, wherein the springincludes a band adapted to circumferentially engage the hub, at leastone biasing feature extending generally radially from the band, and atleast one slack-absorbing feature adapted to tighten the band about thehub.

Other aspects of the disclosed multi-disc brake hub assembly will becomeapparent from the following description, the accompanying drawings andthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of one aspect of the disclosedmulti-disc brake hub assembly;

FIG. 2 is a front elevational view of the hub of the multi-disc brakehub assembly of FIG. 1;

FIG. 3 is a side elevational view of the hub of FIG. 2;

FIG. 4 is a front elevational view of the outer disc of the multi-discbrake hub assembly of FIG. 1;

FIG. 5 is a side elevational view of the outer disc of FIG. 4;

FIG. 6 is a front elevational view of the outer one-piece spring of themulti-disc brake hub assembly of FIG. 1;

FIG. 7 is a front perspective view of the multi-disc brake hub assemblyof FIG. 1 in an assembled configuration;

FIG. 8 is a front perspective view of a portion of the hub of themulti-disc brake hub assembly of FIG. 1, showing the guide pinsconnected thereto; and

FIG. 9 is front elevational view of a portion of the hub of FIG. 7showing the outer disc slidably received over the slide pins.

DETAILED DESCRIPTION

Referring to FIG. 1, one aspect of the disclosed multi-disc brake hubassembly, generally designated 10, may include, among other things,connection bolts 12, 14, 16, 18, 20, an outer disc 22, a hub 26, guidepins 30, 32, 34, 36, 38, 40, 42, an inner disc 44 and, optionally anouter one-piece spring 24 and an inner one-piece spring 44. Themulti-disc brake hub assembly 10 may be connected to the spindle flange46 of a bearing assembly (not shown) by the connection bolts 12, 14, 16,18, 20.

Referring to FIGS. 2 and 3, the hub 26 may include a body 50 and anannulet 52 extending radially from the body 50. The body 50 may beformed as a generally short cylinder and may define a rotational axis A(FIG. 3), a central bore 54 and a plurality of connection bolt receivingbores 56, 58, 60, 62, 64. The annulet 52 may be connected to, or formedintegral with, the body 50 and may define a plurality of guide pinsecuring bores 66, 68, 70, 72, 74, 76, 78. In one aspect, the annulet 52may be positioned generally centrally on the body 50 relative to theaxial length of the body 50.

Those skilled in the art will appreciate that the hub 26 may be formedfrom various rigid materials, such as metal (e.g., steel), using avariety of metal forming processes, such as casting.

Referring to FIGS. 4 and 5, each of the outer 22 and inner 44 discs(only outer disc 22 is shown in FIGS. 4 and 5) may be shaped as a short,hollow cylinder (i.e., an annulus in front view (FIG. 4)) and mayinclude an outer friction surface 80, an inner friction surface 82, anouter radial edge 84, an inner radial edge 86 and a plurality of tabs88, 90, 92, 94, 96, 98, 100. The tabs 88, 90, 92, 94, 96, 98, 100 may bespaced generally equidistantly (or otherwise) from each other and mayextend generally radially inward from the inner radial edge 86.Furthermore, each tab 88, 90, 92, 94, 96, 98, 100 may define a guide pinreceiving bore 102, 104, 106, 108, 110, 112, 114. The tabs 88, 90, 92,94, 96, 98, 100 may be formed integrally with the discs 22, 44 by, forexample, casting or machining the discs. However, those skilled in theart will appreciate that alternative means for forming the tabs 88, 90,92, 94, 96, 98, 100 may be used without departing from the scope of thepresent disclosure (e.g., welding tabs to the discs).

In one aspect, as shown in FIG. 9, the guide pin receiving bores 102,104, 106, 108, 110, 112, 114 may be formed in the tabs 88, 90, 92, 94,96, 98, 100 as generally elongated slots, extending in the radialdirection, to accommodate thermal expansion in the radial direction. Forexample, the elongated slots may be obround in shape, depending upon theshape of the guide pins 30, 32, 34, 36, 38, 40, 42.

As shown in FIG. 8, the guide pins 30, 32, 34, 36, 38, 40, 42 may bereceived through the guide pin securing bores 66, 68, 70, 72, 74, 76, 78in the hub 26 such that an outer portion 116 of each guide pin extendsaxially outwardly from the annulet 52 and an inner portion 118 of eachguide pin extends axially inwardly from the annulet. While the guidepins 30, 32, 34, 36, 38, 40, 42 may be press fit into the guide pinsecuring bores 66, 68, 70, 72, 74, 76, 78, as shown in FIG. 7, thoseskilled in the art will appreciate that the guide pins may be connectedto the hub 26 by alternative means, such as welding, or may be formedintegrally with the hub 26. Alternatively, rather than a single guidepin 30, 32, 34, 36, 38, 40, 42 forming both the outer 116 and the inner118 portions discussed above, two separate guide pins may be used toform the outer and inner portions.

In one aspect, the guide pins 30, 32, 34, 36, 38, 40, 42 may be formedfrom a corrosion resistant material, such as stainless steel. In anotheraspect, the guide pins 30, 32, 34, 36, 38, 40, 42 may be coated with, orotherwise treated with, a corrosion resistant material. Those skilled inthe art will appreciate that the use of corrosion resistant materialsmay reduce corrosion-induced friction and the risk of disc-to-guide pinseizure.

In one aspect, the disclosed multi-disc brake hub assembly 10 may beassembled, as shown in FIG. 7, by (1) connecting the inner disc 44 tothe hub 26 such that the inner portion 118 of each guide pin 30, 32, 34,36, 38, 40, 42 is received through an associated guide pin receivingbore 102, 104, 106, 108, 110, 112, 114 in the inner disc, (2) connectingthe outer disc 22 to the hub 26 such that the outer portion 116 of eachguide pin 30, 32, 34, 36, 38, 40, 42 is received through an associatedguide pin receiving bore 102, 104, 106, 108, 110, 112, 114 in the outerdisc, and (3) passing the connection bolts 12, 14, 16, 18, 20 throughthe connection bolt receiving bores 56, 58, 60, 62, 64 in the hub 26 tosecure the hub to the spindle flange 46 of the knuckle 48. However,those skilled in the art will appreciate that the disclosed multi-discbrake hub assembly 10 may be assembled in a variety of ways withoutdeparting from the scope of the present disclosure.

Accordingly, the outer 22 and inner 44 discs may slide generally in theaxial direction (axis A, FIG. 3) along the guide pins 30, 32, 34, 36,38, 40, 42 in response to a braking force applied to the discs 22, 44 bya caliper piston (not shown).

Optionally, as shown in FIG. 1, the multi-disc brake hub assembly 10 mayinclude an outer one-piece spring 24 and/or an inner one-piece spring28.

Referring to FIG. 6, each of the outer 24 and inner 28 one-piece springs(only the outer one-piece spring 24 is shown in FIGS. 6, 8 and 9) mayinclude a generally continuous band 120, features 122, 124, 126, 128,130, 132, 134 that bias the spring, and features 136, 138, 140, 142,144, 146, 148 that take up slack in the spring. The spring may alsoinclude axial position retention tabs 150, 152, 154, 156, 158, 160, 162and circumferential position retention tabs 164, 166, 168, 170, 172,174, 176 having a guide pin opening 178 therein. The one-piece spring 24may be formed from any appropriate rigid material (e.g., steel or thelike).

As shown in FIG. 8, the outer one-piece spring 24 may be positionedcircumferentially over the outer portion 53 (FIG. 3) of the body 50 ofthe hub 26. The slack-absorbing features 136, 138, 140, 142, 144, 146,148 may provide tension to the band 120 by absorbing slack in the band.Therefore, the slack-absorbing features 136, 138, 140, 142, 144, 146,148 may facilitate a tight tolerance between the outer one-piece spring24 and the outer portion 53 of the body 50 of the hub 26. The axialposition retention tabs 150, 152, 154, 156, 158, 160, 162 may bereceived in a circumferential groove 178 extending about the body 50 ofthe hub 26, thereby restricting movement of the outer one-piece spring24 in the axial direction relative to the central axis A (FIG. 3) of themulti-disc brake hub assembly 10. The circumferential position retentiontabs 164, 166, 168, 170, 172, 174, 176 may be positioned to receive(e.g., straddle) an associated guide pin 30, 32, 34, 36, 38, 40, 42 byway of the guide pin opening 178 thereof, thereby restrictingcircumferential rotation of the outer one-piece spring 24 about thecentral axis A relative to the hub 26.

As shown in FIG. 9, the each biasing feature 122, 124, 126, 128, 130,132, 134 may engage an associated tab 88, 90, 92, 94, 96, 98, 100 of theouter disc 22 to apply a biasing force (arrow F) to the tab in both theradial and circumferential directions. A chamfer 182 may be formed ineach tab 88, 90, 92, 94, 96, 98, 100 to facilitate the interactionbetween the biasing springs 122, 124, 126, 128, 130, 132, 134 and thetabs.

The inner one-piece spring 28 may be applied to the inner portion 55 ofthe body 50 of the hub 26 in a similar fashion as the outer one-piecespring 24 is applied to the outer portion 53 of the body 50 of the hub26.

Accordingly, those skilled in the art will appreciate that the outer andinner one-piece springs 24, 28 may reduce disc rattle by exerting both aradial and circumferential (relative to axis A) force to the disks 22,44. Furthermore, those skilled in the art will appreciate that the outerand inner one-piece springs 24, 28 may be used with the disclosedmulti-disc brake hub assembly 10, as well as with other (e.g.,traditional) multi-disc brake hub assemblies.

Although various aspects of the disclosed multi-disc brake hub assemblyhave been shown and described, modifications may occur to those skilledin the art upon reading the specification. The present applicationincludes such modifications and is limited only by the scope of theclaims.

1. A brake hub assembly comprising: a hub defining a central axis; aplurality of guide pins, each of said plurality of guide pins extendingfrom said hub and being generally aligned with said central axis; and adisc having at least two friction surfaces, said disc defining aplurality of guide pin receiving bores, wherein each of said pluralityof guide pin receiving bores are positioned to receive an associated oneof said plurality of guide pins therethrough such that said disc ismoveable relative to said hub along said central axis.
 2. The brake hubassembly of claim 1 wherein said hub includes a body and an annulet, andwherein said guide pin receiving bores are in said annulet.
 3. The brakehub assembly of claim 2 wherein annulet extends generally radially fromsaid body.
 4. The brake hub assembly of claim 2 wherein said body isgenerally cylindrical in shape.
 5. The brake hub assembly of claim 2further comprising a one-piece spring circumferentially disposed aboutsaid body of said hub, said one-piece spring including a plurality ofbiasing features adapted to apply a biasing force to said disc.
 6. Thebrake hub assembly of claim 5 wherein said biasing force is applied in aradial direction and a circumferential direction relative to saidcentral axis.
 7. The brake hub assembly of claim 5 wherein saidone-piece spring includes at least one slack-absorbing feature.
 8. Thebrake hub assembly of claim 5 wherein said one-piece spring includes atleast one of an axial position retention tab and a circumferentialposition retention tab.
 9. The brake hub assembly of claim 1 whereineach of said plurality of guide pins includes a corrosion resistantmaterial.
 10. The brake hub assembly of claim 9 wherein said corrosionresistant material is stainless steel.
 11. The brake hub assembly ofclaim 1 wherein said hub defines a plurality of guide pin securing boresand each of said plurality of guide pins is positioned in an associatedone of said plurality of guide pin securing bores.
 12. The brake hubassembly of claim 11 wherein said guide pins are press fit into saidguide pin securing bores.
 13. The brake hub assembly of claim 1 whereinsaid disc includes a plurality of tabs, each of said plurality of tabsdefining an associated one of said plurality of guide pin receivingbores.
 14. The brake hub assembly of claim 1 wherein each of saidplurality of guide pin receiving bores is generally elongated.
 15. Thebrake hub assembly of claim 1 wherein each of said plurality of guidepin receiving bores is generally elongated in a radial directionrelative to said central axis.
 16. The brake hub assembly of claim 1further comprising a second disc having at least two friction surfacesand defining a plurality of guide pin receiving bores, wherein each ofsaid plurality of guide pin receiving bores of said second disc arepositioned to receive an associated one of said guide pins therethroughsuch that said second disc is moveable relative to said hub and saiddisc along said central axis.
 17. A brake hub assembly comprising: a hubdefining a central axis and including a body and an annulet, saidannulet defining a outer side and an inner side relative to said centralaxis; a plurality of outer guide pins extending from said annulet onsaid outer side of said hub, each of said plurality of outer guide pinsbeing generally aligned with said central axis; a plurality of innerguide pins extending from said annulet on said inner side of said hub,each of said plurality of inner guide pins being generally aligned withsaid central axis; an outer disc defining a plurality of guide pinreceiving bores positioned to receive an associated one of saidplurality of outer guide pins therethrough, wherein said outer disc ismoveable along said plurality of outer guide pins relative to said hub;and an inner disc defining a plurality of guide pin receiving borespositioned to receive an associated one of said plurality of inner guidepins therethrough, wherein said inner disc is moveable along saidplurality of inner guide pins relative to said hub.
 18. The brake hubassembly of claim 17 wherein each of said plurality of outer guide pinsextends through said annulet to form an associated one of said pluralityof inner guide pins.
 19. The brake hub assembly of claim 17 furthercomprising an one-piece spring circumferentially disposed about saidbody of said hub, said one-piece spring including a plurality of biasingfeatures adapted to apply a biasing force to said outer disc.
 20. Aspring for applying a biasing force to a disc of a multi-disc brake hubassembly including a hub, said spring comprising: a band adapted tocircumferentially engage said hub; at least one biasing featureextending generally radially from said band; and at least oneslack-absorbing feature adapted to tighten said band about said hub. 21.The spring of claim 20 further comprising at least one axial positionretention tab extending generally radially inward relative to said band.22. The spring of claim 20 further comprising at least onecircumferential position retention tab extending radially outwardrelative to said band.
 23. The spring of claim 20 wherein said hubincludes at least one guide pin extending therefrom and saidcircumferential position retention tab defines a guide pin openingtherein, and wherein said guide pin is received in said guide pinopening.